Piston for internal combustion motors



Jan.'7, 1.936; u E. c. LONG 2,026,789 PISTON FOR INTERNAL COMBUSTION MOTORS Filed Sept. 9, 1952 Patent ed Jan. 7, ,1936

,UNlTE W jSTATES.

PATENT OFFlCE PISTON JOB INTERNAL COMBUSTION MOTORS Elmer C. Long, irosse Pointe Park, Mich. Application September 9, 1932, Serial No. 632,326

3 Claims. (01. 309-11) This invention relates to improvements in pistons and is a furthering of the improvements disclosed in my pending application Serial Number 625,586 filed July 29, 193-2, this application however difiering from saidpending application in that the piston skirt has no separated section 0 slipper.

The primary object of this invention isvto pro which is efiective thereon when the piston is under the influence or heat.

A further object of the invention is in providing a piston with an approximate full skirt having an improved rigid construction on the power thrust side and a flexible structure on the com pression thrust side 01. the skirt.

Other and further objects will appear in the specification and be specifically pointed out in the appended claims, reference being had to' the accompanying drawing, exemplifying the invention, and in which:-- i v Figure 1 is a longitudinal vertical section taken through the pin boss sides of this improved pis- 1 ton.

Figure 2 is a longitudinal vertical section taken approximately on the line 11-11 of Fig. l.

, Figure 3 is a horizontal section taken approximately on the line lIIHI oi! Fig. 1.

The accompanying drawing discloses a piston having a head I and a side wall 2 depending from the head having packing ring grooves 3 formed therein and depending from opposing sides of the side wall 2 are pairs of legs 4 for the support 01 pin bosses 5. The legs 4 at their upper ends join with the head and with each other. Extending from one side of each pin boss is a web 6, said webs at their extending ends joining with the skirt I on the power thrust side 8 01' the skirt, the pin bosses 5 each being free from engagement with the skirt by the gap or slot' 9 on each pin boss side of the skirt, each or said gaps 9 encompassing the underside of respective pin bosses and the supporting legs 4. I

The head I of the piston is partially separated from the skirt 1 by the transverse slot l0 which is joined at its ends with the upper ends 9:: of respective slots 9 on the compression thrust side ll of the skirt and in alinement with said transverse slot III on the power thrust side 8 adjacent each pin boss, is a transverse slotting li'la with which the ends 8b of the slots Sare connected. y

The transverse slots Ilia on each pin boss side of the skirt.v are relatively short in length as shown in Fig. 2 thereby leaving an intermediately disposed portion I! with whichthe power thrust side 8 of the skirt is connected to the side 10 wall 2 of the piston head I, the direct connection of the power thrust side 8 with the head through the intermediate portion l2, being capable of presenting a solid thrust side to the cylinder wall particularly by the reinforcement of 18 the web 6 from respective pin bosses 5 to the power thrust side 8.

The compression thrust side Hot the skirt is.

provided with a longitudinal slot l3 which extends from the open end l4 ot'the skirt to adjacent a horizontal plane through the pin boss axis as shown in Figs. 1 arid 2, thelongitudinal slot l3 being for the purpose of providing'flexibility to the approximate lower half of the compression thrust side II.

The approximate upper half portion of the'.

compression thrust side II which is'in the form or a tongue-shaped portion Ii a by reason of the slottings 9 and I0, is provided with a bridge structure I 5 comprising an arcuate vertical wall or web [6 which is connected at its ends to the outer end of respective pin bosses 5 as shown more clearly in Fig. 3, and formed integral with said wall It are a pair of diverging webs [1 which join the central portion or the compression thrust side ll of the skirt. r

The wall l6 and the inclined web I! in the casting operation of the piston are extended to the head I, and in the machining, the cutting operation required for making the slot or gap In will sever the arcuate wall It and the joining web I! from the head.

The slotting of the compression thrust sidev ll of the skirt and the bridge structureIB thereof, provides a flexible thrust side which is resiliently yieldable and in the machining and finishing of the piston, the skirt may be provided with a relative .small clearance such as.002 of an inch for fitting the piston in the cylinder of an internal combustion motor, as in a piston of this improved character, a clearance otapproximately .002 is sumcient to prevent back-slap of the piston in v the cylinder during the starting of the motor or when the motor is running cold. Upon heated conditions occurring within the cylinder, the

. head I by reason of receiving expanding burning I thrusts from gaseous charges will obviously receive the maximum of heat and consequently a maximum of expansion. As the head expands, the opposing pin bosses 5 which are connected to respective ends of the .arcuate wall l6, willbe moved outwardly by the expansion of the head across the pin boss diameter and the arcuate wall I6 by reason of the separating forces of the pin bosses, will tend to straighten or lengthen the wall l6 and in so doing will tend to pull or hold the tongue-shaped Ila or upper half portion of the; compression thrust side ll inwardly and whereas the longitudinal slot l3 by reason of weakening the lower portion of the thrust side II will obviously permit inward movement for flexing of the lower portion of the thrust side II.

It is therefore seen that when the piston is in operation in its cylinder, the compression thrust side II by reason of it being flexible and resiliently yieldable, is capable of a limited bodily movement towards or away from the center of the piston, due to its flexible connection with the pin bosses, during changing thermal conditions of the piston and cylinder.

From the above description of this improved piston, it is obvious that a solid or rigid structure is provided on the power thrust side 8 of the piston for receiving the angular power thrusts of the connecting rod of the piston andwhereas any take-up required due to expansion of the piston, will be compensated for by the resiliently yieldable flexiblecompression thrust side H of the skirt and at the same time, a full or solid wall skirt is provided.

Having thus described the invention so-that those skilled in the art will be able to practice the same, what I desire to secure by Letters Patent is defined in what is claimed, it being understood aozenso that various changes in the device shown and described above in detail and not amounting to invention, may be made without departing from the spirit and scope of my invention.

What I claim is:

1. A piston having a head, a skirt, pin bosses separated from the skirt, said skirt being separated from the head except on one of its thrust sides, and a transversely disposed-member connected at its ends to one side of respective pin bosses and having connection with the other thrust side of said skirt, said last mentioned thrust side being longitudinally slotted, and the skirt being circumferentially continuous from the slot for providing an approximate full cylinder bearing skirt.

2. A piston having a head, a skirt, pin bosses separated from the skirt, said skirt being separated from the head except on one of its thrust sides, and a transverse arcuate member connected at its ends to the outer ends of respective pin bosses, said transverse member having intermediately disposed diverging webs connecting the other thrust side of the skirt, said skirt having a longitudinal slot on one of its thrust sides and being circumferentially con inuous from the slot. 3. A piston having a head, a skirt, pin bosses separated from the skirt, the skirt beneath the pinbosses being circumferentially continuousv said skirt being separated from the head except on one of its thrust sides, said skirt on its oppo- 

